SCOTT SIMON, HOST:
Marijuana use among teens has grown in the past decade, and researchers have been trying to better understand the health risks. Now a new study finds that cannabis use among teens increases risks of being diagnosed with bipolar and psychotic disorder years later. NPR’s Rhitu Chatterjee has more.
RHITU CHATTERJEE, BYLINE: Researchers analyzed health data on nearly half a million teenagers in the Kaiser Permanente health system in Northern California. The data included annual screenings for substance use and any mental health diagnoses all the way until they were young adults. Pediatrician Dr. Lynn Silver at the Public Health Institute in California is one of the authors of the study.
LYNN SILVER: We looked at kids using cannabis before they had any evidence of these psychiatric conditions and then followed them to understand if they were more likely or less likely to develop them.
CHATTERJEE: They found that the teens who reported using cannabis in the past year were at a higher risk of being diagnosed with several mental health conditions a few years later, compared to teens who didn’t use cannabis.
SILVER: What we found is extremely worrisome.
CHATTERJEE: The highest risk was for two disorders – bipolar, which manifests as alternating symptoms of depression and mania, and psychotic disorders.
SILVER: And psychotic disorders means ones where you hear or see things that aren’t real. Typically, it can be anything from an episode to actual schizophrenia.
CHATTERJEE: Now, only a small percentage – about 1% of the teens – were diagnosed with these two disorders, but the risk of developing them doubled for teens who used cannabis versus those who didn’t. Silver notes that both bipolar and psychotic disorders are among the most serious and disabling of mental illnesses. The risk for more common conditions, like depression and anxiety, was also higher among cannabis users. Silver hopes that the study published in JAMA Health Forum will make teens more cautious about using the drug, which is not as safe as they think it is.
SILVER: With legalization, we’ve had a tremendous wave of misperception of cannabis as a safe, natural product to treat your stress with.
CHATTERJEE: Psychiatrist Dr. Ryan Sultan at Columbia University also researches the impacts of cannabis use on teens but wasn’t involved in the new study. He finds the results worrying, and it confirms what he’s seeing in his clinic, more teens using cannabis who’ve developed new or worsening mental health symptoms.
RYAN SULTAN: It is most common around anxiety and depression, but it’s also showing up in more severe conditions like bipolar disorder and psychosis.
CHATTERJEE: He notes that mental health disorders are complex in origin. A host of risk factors, like genetics, our environment, lifestyle and life experiences, all play a role, and some young people are more at risk than others.
SULTAN: Which is why when someone has a psychotic episode in the context of cannabis or a manic episode in the context of cannabis, you know, clinicians are going to say, please do not do that again because you’re playing with fire.
CHATTERJEE: Because the more they use the drug he says, the more likely their symptoms will worsen over time, making recovery harder.
Rhitu Chatterjee, NPR News.
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